Effect of Soluble Corn Fiber Supplementation for 1 Year on Bone Metabolism in Adolescents

The primary aim of this proposal is to determine the effects of soluble corn fiber (SCF) supplementation for 1 year on bone metabolism in growing adolescents compared to controls. For the proposed study, a randomized double-blinded placebo controlled clinical trial will be conducted in 236 healthy adolescents aged 10-13 years, equally randomly assigned to one of four intervention groups: SCF (12 g/d), SCF + calcium (12 g/d of SCF + 600 mg/d of elemental calcium), placebo (0 g/d of SCF or of calcium), and placebo + calcium (0 g/d of SCF + 600 mg/d of elemental calcium); all administered twice a day. Bone mass will be assessed at baseline at 6 months and at 12 months and bone related biomarkers and fecal microbiome will be assessed at baseline and at 12 months.

The adolescent period is crucial for optimizing future bone health because bone accumulates rapidly during these years and accounts for up to half of adult peak bone mass. Calcium intake during this period is critical for adequate bone mineralization but this is the nutrient most deficient in the diets of adolescents. A strategy to maximize bone mineralization during this critical period is to increase the absorption of the calcium being consumed. This could be achieved by supplementing diets with certain non-digestible carbohydrates, such as soluble corn fiber (SCF). The primary aim of this study is to determine the effects of SCF supplementation for 1 year on bone metabolism in growing adolescents compared to controls. A randomized double-blinded placebo controlled clinical trial will be conducted in 236 healthy adolescents aged 10-13 years, equally randomly assigned to one of four intervention groups: SCF (12 g/d), SCF + calcium (12 g/d of SCF + 600 mg/d of elemental calcium), placebo (0 g/d of SCF or of calcium), and placebo + calcium (0 g/d of SCF + 600 mg/d of elemental calcium); all administered twice a day. Bone mass will be assessed at baseline at 6 months and at 12 months and bone related biomarkers and fecal microbiome will be assessed at baseline and at 12 months. The treatments will be provided in the form of flavored drinks twice per day (this was previously used in a short-term study among adolescents with excellent acceptance). Bone mass and anthropometric measurements will be assessed at baseline, at 6 months and at 12 months and bone related biomarkers and fecal microbiome will be assessed at baseline and at 12 months. Assessment visits will be conducted in the Clinical Research Center of the Stempel School of Public Health at Florida International University. We will also have short home visits at 3 and 9 months to collect unused supplements and provide more supplements. In all visits, participants will complete several questionnaires, such as general health, diet and activity questionnaire. Compliance will be evaluated at all visits and also in real time using a study mobile app. The primary outcome is change in bone mineral content (BMC) measured using Dual-energy X-ray absorptiometry (DXA) The secondary outcomes include biochemical markers reflecting vitamin D status, calcium homeostasis and bone, such as serum calcium, phosphorus, creatinine, osteocalcin, carboxy-terminal collagen crosslinks (CTX), parathyroid hormone (PTH), bone specific alkaline phosphatase, 25-(OH) vitamin D3, 1,25-(OH)2 vitamin D3, and insulin growth factor 1 (IGF-I) and urinary calcium, phosphorus, creatinine and N-telopeptide cross-links.

This group will receive 12 g/d of soluble corn fiber (SCF) + 600 mg/d of elemental calcium carbonate, administered twice a day

This group will receive 12 g/d of soluble corn fiber (SCF) + 600 mg/d of elemental calcium carbonate, administered twice a day

This group will receive a similar supplement without SCF + 600 mg/d of elemental calcium carbonate, administered twice a day

Participants will consume a supplement with 12 g/day of SCF + calcium carbonate (600 mg/day) for 12 months

Participants will undergo a bone scan at baseline, at 6 months and at 12-months follow-up visits using a dual energy x-ray absorptiometry (DXA)

Participants will undergo a bone scan at baseline, at 6 months and at 12-months follow-up visits using a dual energy x-ray absorptiometry (DXA)

Vitamin D status will be measured as serum 25(OH)D at baseline and 12-months follow-up visits using standard ELISA kits.

It will be measured at baseline and 12-months follow-up visits from a serum sample using standardized kits

It will be measured at baseline and 12-months follow-up visits from a serum sample using standardized kits

It will be measured at baseline and 12-months follow-up visits from a serum sample using standardized kits

It will be measured at baseline and 12-months follow-up visits from a serum sample using standardized kits

It will be measured at baseline and 12-months follow-up visits from a serum sample using standardized kits

It will be measured at baseline and 12-months follow-up visits from a serum sample using standardized kits

It will be measured at baseline and 12-months follow-up visits from a serum sample using standardized kits

It will be measured at baseline and 12-months follow-up visits from a 24-h urine sample using standardized kits

It will be measured at baseline and 12-months follow-up visits from a 24-h urine sample using standardized kits

It will be measured at baseline and 12-months follow-up visits from a 24-h urine sample using standardized kits

It will be measured at baseline and 12-months follow-up visits from a 24-h urine sample using standardized kits

Participants will undergo a bone scan at baseline, at 6 months and at 12-months follow-up visits using a dual energy x-ray absorptiometry (DXA)

Participants will undergo a bone scan at baseline, at 6 months and at 12-months follow-up visits using a dual energy x-ray absorptiometry (DXA)

Participants will undergo a bone scan at baseline, at 6 months and at 12-months follow-up visits using a dual energy x-ray absorptiometry (DXA)

Participants will provide a fecal sample at baseline and at 12-months follow-up visits using 16S ribosomal RNA (or 16S rRNA) gene sequences

Inclusion Criteria: Body mass index between the 5th and 85th percentiles for age and sex based on the Centers for Disease Control Growth Charts. Exclusion Criteria: Subjects with any chronic illness requiring regular medication use. Those taking calcium supplements (>500 mg/d) and vitamin D supplements (>400 IU/d) on a regular basis

Investigators outside the research team will only be granted access to the data after their proposal has been evaluated and approved by the research team and by the Florida International University Office of Research Integrity. We will only provide access to the samples and de-identified data as required to address the proposed research goals and only under a data-sharing agreement.

We will share the data and associated documentation only under a data-sharing agreement that provides for: (1) a commitment to using the data only for research purposes and not to identify any individual participant; (2) a commitment to securing the data using appropriate computer technology; and (3) a commitment to destroying or returning the data after analyses are completed.